Title: SecD is involved in the release of translocated secretory proteins from the cytoplasmic membrane of Escherichia coli.
Abstract: Research Article1 January 1993free access SecD is involved in the release of translocated secretory proteins from the cytoplasmic membrane of Escherichia coli. S. Matsuyama S. Matsuyama Institute of Applied Microbiology, University of Tokyo, Japan. Search for more papers by this author Y. Fujita Y. Fujita Institute of Applied Microbiology, University of Tokyo, Japan. Search for more papers by this author S. Mizushima S. Mizushima Institute of Applied Microbiology, University of Tokyo, Japan. Search for more papers by this author S. Matsuyama S. Matsuyama Institute of Applied Microbiology, University of Tokyo, Japan. Search for more papers by this author Y. Fujita Y. Fujita Institute of Applied Microbiology, University of Tokyo, Japan. Search for more papers by this author S. Mizushima S. Mizushima Institute of Applied Microbiology, University of Tokyo, Japan. Search for more papers by this author Author Information S. Matsuyama1, Y. Fujita1 and S. Mizushima1 1Institute of Applied Microbiology, University of Tokyo, Japan. The EMBO Journal (1993)12:265-270https://doi.org/10.1002/j.1460-2075.1993.tb05652.x PDFDownload PDF of article text and main figures. ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InMendeleyWechatReddit Figures & Info The SecD protein is one of the components that has been suggested from genetic studies to be involved in the protein secretion across the cytoplasmic membrane of Escherichia coli. We examined the effect of anti-SecD IgG on protein secretion using spheroplasts. Inhibition of the secretion of OmpA and maltose-binding protein (MBP) by this IgG was observed with concomitant accumulation of their precursor and mature forms in spheroplasts. This effect was specific to anti-SecD IgG. Anti-SecE and anti-SecY IgGs, of which the epitopes are located at the periplasmic domains of SecE and SecY, respectively, did not interfere with the secretion. Time-course experiments investigating the processing of proMBP and the release of MBP from spheroplasts revealed that anti-SecD IgG interfered with the release of the translocated mature MBP. The mature form of MBP thus accumulated was sensitive to trypsin, which was externally added to spheroplasts, whereas MBP released into the medium was resistant to trypsin as the native MBP is. The precursor form of MBP accumulated in spheroplasts was also trypsin resistant. We conclude that SecD is directly involved in protein secretion and important for the release of proteins that have been translocated across the cytoplasmic membrane. Previous ArticleNext Article Volume 12Issue 11 January 1993In this issue RelatedDetailsLoading ...